Summary of Work: Efforts are continuing to visualize G-proteins as they exist in cultured cells employing imaging techniques, including confocal microscopy. As reported previously, different types of punctate structures are visualized within the cells that seem separate from tubuli and acting structures. Unfortunately, thee are major impediments for high-resolution investigations of these structures. Efforts are underway to utilize fluorescent tagging of G-protein subunits as another means of identifying the distribution of these structures in cells transfected with appropriate tagged G-proteins. Another avenue of research deals with the question of multimeric structures of G-proteins. The beta adrenergic receptor has been fused with the GS alpha subunits and transfected into cells. An intriguing result is that the transfected material, when exposed to agonist results in activation not only of the G-protein fused with the receptor but also of the endogenous GS. Although indirect this result suggests that the endogenous GS proteins become associated with the transfected G to form an oligomeric structure in accord with all of our previous studies. - g-proteins, signal transduction, adenylyl cyclase, cytoskeleton